The invention relates to a safety ski binding and, in particular, to a ski binding providing an improved heel support.
A typical heel support is described in Austrian Patent Publication No. AT-A2-296,111. This publication discloses a jaw body which is rotatably mounted on a pivot in the heel support. A support plate and a sole support are linked eccentrically to the pivot. This design does not take certain geometrical requirements of a ski binding into account. For example, the axis of rotation for the ski boot about the support plate is not in the extension of the shinbone axis. As a result, the maximum admissible torque of the shinbone cannot be accurately adjusted. In addition, in some ski bindings the control mechanism is designed to ensure that the horizontal and vertical releases are exactly matched, thereby requiring very narrow design limitations. Further, conventional ski bindings are oftentimes oversized and correspondingly heavy.
German Patent Publication No. DE-A1-34 45 760 discloses a pivot on a base plate, in which the pivot is disposed between a front jaw and a heel support. In this device, the support plate is designed as a continuous sole plate and is pivotally mounted. However, this sole plate is designed in two parts, the first part being mounted at the pivot and the two parts of the sole plate being capable of being pivoted jointly about the pivot. The second part is designed in frame-like fashion relative to the first part and can be additionally pivoted upwardly about a transverse axle being mounted in the first part. This design of sole plate is expensive and requires a lot of time and effort to construct.
German Patent Publication No. DE-A1-23 40 420 discloses control means for pushing a support plate into a central position on the ski. In this publication, a heel support is provided with a spring disposed in the longitudinal direction of the ski and a roller which cooperates with a control cam. However, this heel support does not have any support plate on which the ski boot would be supported with its sole at least in the heel area. According to this design, a separate plate is provided to mount the heel support which pivots about a vertical axis. The heel of the ski boot is required to rest on a component that is rigidly attached to the ski. The control means thus determines only the pivoting capability of the heel support in the horizontal plane and the ski boot heel rubs against the component rigidly attached to the ski.
German Patent Publication No. DE-A1-28 51 634 discloses a ski binding in which a roller of the control mechanism is disposed at an element located in parallel to the support plate designed as base plate. However, the axis of this roller extends transversely to the longitudinal axis of the ski, the roller cooperating with an exposed cam designed in a V-shaped fashion. Due to this construction, impurities easily result from snow, ice and the like which prevent precise control of the ski binding.
In another publication, "Tech 60", Technical Manual of Tyrolia, 1979, the use of spring force is disclosed in connection with control of a heel support.
A binding with a sole plate supporting a non-releasing front jaw at its front end area is described in Austrian Patent Publication No. AT-PS 330,632. In this binding a control or locking means is provided for the locking of the heel support and the sole plate, which is located at an extension of the sole plate. Since a release takes place both in the case of a forward fall and a torsion fall of the skier by the heel support alone, the sole plate must be pivotable about a vertical axis and tiltable about a transverse axis. The tilting movement entails, however, difficulties with respect to the mounting of the sole plate on the vertical axle. Further, due to the special design of the control or locking means, narrow limits are set to an exact matching of horizontal and vertical releases. Moreover, the construction of the entire binding is somewhat over-dimensioned due to construction considerations such as high weight.